Assessing Aortic Stenosis using Sample Entropy of the Phonocardiographic Signal in Dogs
2008 (English)In: IEEE Transactions on Biomedical Engineering, ISSN 0018-9294, Vol. 55, no 8, 2107-2109 p.Article in journal (Refereed) Published
In aortic valve stenosis (AS), heart murmurs arise as an effect of turbulent blood flow distal to the obstructed valves. With increasing AS severity, the flow becomes more unstable, and the ensuing murmur becomes more complex. We hypothesize that these hemodynamic flow changes can be quantified based on the complexity of the phonocardiographic (PCG) signal. In this study, sample entropy (SampEn) was investigated as a measure of complexity using a dog model. Twenty-seven boxer dogs with various degrees of AS were examined with Doppler echocardiography, and the peak aortic flow velocity (Vmax) was used as a reference of AS severity. SampEn correlated to Vmax with R = 0.70 using logarithmic regression. In a separate analysis, significant differences were found between physiologic murmurs and murmurs caused by AS (p < 0.05), and the area under a receiver operating characteristic curve was calculated to 0.96. Comparison with previously presented PCG measures for AS assessment showed improved performance when using SampEn, especially for differentiation between physiological murmurs and murmurs caused by mild AS. Studies in patients will be needed to properly assess the technique in humans.
Place, publisher, year, edition, pages
2008. Vol. 55, no 8, 2107-2109 p.
Aortic stenosis (AS), bioacoustics, heart sound, murmur, sample entropy (SampEn)
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-13042DOI: 10.1109/TBME.2008.923767OAI: oai:DiVA.org:liu-13042DiVA: diva2:17715